An Essay Concerning Human Understanding
By
John Locke
Book II:
Of Ideas, Chapters 12-33

It is worth our observing, which of all our simple ideas have been MOST modified, and had most mixed ideas made out of them, with names given to them. And those have been these three: — THINKING and MOTION (which are the two ideas which comprehend in them all action,) and POWER, from whence these actions are conceived to flow. These simple ideas, I say, of thinking, motion, and power, have been those which have been most modified; and out of whose modifications have been made most complex modes, with names to them. For ACTION being the great business of mankind, and the whole matter about which all laws are conversant, it is no wonder that the several modes of thinking and motion should be taken notice of, the ideas of them observed, and laid up in the memory, and have names assigned to them; without which laws could be but ill made, or vice and disorders repressed. Nor could any communication be well had amongst men without such complex ideas, with names to them: and therefore men have settled names, and supposed settled ideas in their minds, of modes of actions, distinguished by their causes, means, objects, ends, instruments, time, place, and other circumstances; and also of their powers fitted for those actions: v.g. BOLDNESS is the power to speak or do what we intend, before others, without fear or disorder; and the Greeks call the confidence of speaking by a peculiar name, [word in Greek]: which power or ability in man of doing anything, when it has been acquired by frequent doing the same thing, is that idea we name HABIT; when it is forward, and ready upon every occasion to break into action, we call it DISPOSITION. Thus, TESTINESS is a disposition or aptness to be angry.

To conclude: Let us examine any modes of action, v.g. CONSIDERATION and ASSENT, which are actions of the mind; RUNNING and SPEAKING, which are actions of the body; REVENGE and MURDER, which are actions of both together, and we shall find them but so many collections of simple ideas, which, together, make up the complex ones signified by those names.

11. Several Words seeming to signify Action, signify but the effect.

POWER being the source from whence all action proceeds, the substances wherein these powers are, when they *[lost line??] exert this power into act, are called CAUSES, and the substances which thereupon are produced, or the simple ideas which are introduced into any subject by the exerting of that power, are called EFFECTS. The EFFICACY whereby the new substance or idea is produced is called, in the subject exerting that power, ACTION; but in the subject wherein any simple idea is changed or produced, it is called PASSION: which efficacy, however various, and the effects almost infinite, yet we can, I think, conceive it, in intellectual agents, to be nothing else but modes of thinking and willing; in corporeal agents, nothing else but modifications of motion. I say I think we cannot conceive it to be any other but these two. For whatever sort of action besides these produces any effects, I confess myself to have no notion nor idea of; and so it is quite remote from my thoughts, apprehensions, and knowledge; and as much in the dark to me as five other senses, or as the ideas of colours to a blind man. And therefore many words which seem to express some action, signify nothing of the action or MODUS OPERANDI at all, but barely the effect, with some circumstances of the subject wrought on, or cause operating: v.g. CREATION, ANNIHILATION, contain in them no idea of the action or manner whereby they are produced, but barely of the cause, and the thing done. And when a countryman says the cold freezes water, though the word freezing seems to import some action, yet truly it signifies nothing but the effect, viz. that water that was before fluid is become hard and consistent, without containing any idea of the action whereby it is done.

12. Mixed Modes made also of other Ideas than those of Power and Action.

I think I shall not need to remark here that, though power and action make the greatest part of mixed modes, marked by names, and familiar in the minds and mouths of men, yet other simple ideas, and their several combinations, are not excluded: much less, I think, will it be necessary for me to enumerate all the mixed modes which have been settled, with names to them. That would be to make a dictionary of the greatest part of the words made use of in divinity, ethics, law, and politics, and several other sciences. All that is requisite to my present design, is to show what sort of ideas those are which I call mixed modes; how the mind comes by them; and that they are compositions made up of simple ideas got from sensation and reflection; which I suppose I have done.